Evidence filed in a lawsuit against the government of Saudi Arabia over its alleged involvement in the 9/11 terror attacks of 2001 suggests the Saudi embassy in Washington may have helped Al Qaeda terrorists prepare for the attacks on the World Trade Center that killed nearly 3,000 people.

According to a report in the New York Post, briefs filed on behalf of 1,400 relatives of victims of the attacks provide evidence that the Saudi government, through its embassy in Washington DC, paid two Saudi nationals to fly from Phoenix, Arizona to Washington.

The court brief claims the trip was a "dry run" for the attack, allowing the two Saudi men to test flight deck security and assess the feasibility of the plot to hijack aircraft and fly them into the World Trade Center.

This latest evidence, the plaintiffs claim, is only the latest proof for a relationship they say has been well-known for years.

"We've long asserted that there were longstanding and close relationships between Al Qaeda and the religious components of the Saudi government," said attorney Sean Carter, who heads the legal team suing Saudi Arabia.

The Saudi government has long denied involvement in the 9/11 attacks or support for the Al Qaeda terrorist organization.

Last year, Congress passed legislation opening the door to lawsuits against Saudi Arabia, prompted in part by evidence collected over the past 15 years, suggesting possible ties between the Saudi embassy and the 9/11 attackers.

American authorities discovered the flight certificate of would-be hijacker Ghassan Al-Shrabi in an envelope from the Saudi embassy to Washington during the latter's 2002 arrest in Pakistan, officials revealed at the time.

Details about the certificate and other documents were quietly released by officials in 2015, in a memo entitled Document 17 from back in 2003.

Congress in July released 28 previously secret pages of the report detailing suspicious Saudi ties to the 9/11 hijackers, but it failed to include a smoking gun definitively linking the kingdom to the terrorist attacks.

Al-Qaeda marked the 16th anniversary of 9/11 by releasing previously unseen footage of Mohand al-Shehri, one of the hijackers aboard United Airlines Flight 175 that crashed into the South Tower of the World Trade Center, noting that the terrorists have "longed for your beautiful lands" and find the blood of Americans "delicious."

Al-Shehri, 22, was a Saudi who trained in Chechnya and Afghanistan months before being granted a student visa to the United States. He arrived in the U.S. four months before the attacks and trained on a flight simulator in Vero Beach, Fla.

According to the video, al-Shehri shot the statement April 17, 2001, before he arrived in the United States that May….

It begins with a few minutes of archive footage of late al-Qaeda leader Osama bin Laden before moving on to al-Shehri reading his statement. "The tyrants have led the ummah [Muslim community] to this abyss. Filth and immorality have become widespread and has deprived the hearts of sobriety and filled them with lowliness," he said.

"So accompany me in this last will as I address you from the deck of my ship as to guide you to the shores of salvation. Perhaps your boat will hear my words of inspiration and rock with enthusiasm and you would stop in your way and change course to head for the gardens of eternity. Allah will surely replace those who have chosen to sit back and refrain from the obligation of jihad with others who will rise and act on the basis of the Islamic creed, be willing to pay the price of honor and overcome the enemies of Allah," he continued. "Those who have chosen to sit back will then be left worthless, and their reckoning will neither be delayed nor hastened, for Allah is all-powerful and nothing can stop him from replacing you with another people."…

Al-Shehri vowed that "this ummah has been molded by the Quran and the sword, and neither of them can be separated from the other," and decried the "Judaization of Palestine."

"If we abandon this cause, do not wake up from our slumber and do not dedicate to this cause except for the little spare time that we have, the Arabian Peninsula itself will become a killing ground of Muslims, just like Palestine," he said, stressing that jihadists need to "defeat America and the Cross."

"America, where shall you escape? The sea is behind you, we are in front of you, and there is no way out. If you accept Islam, you shall be safe and Allah will give you your reward and the reward of those after you, or else just wait for us. With the permission of Allah, we are coming to sever your heads, rip apart your bellies and make you fall over yourselves. You will be looking for rescue and there will be no way out. There will be no solution for you except death and then even more death," he continued.

"We have longed for your beautiful lands, for its streams and trees, palaces and lakes. We have resolved to tread upon your lands and embrace the maidens of paradise on your soil. Your blood is delicious for us and your meat cheap. We are thirsty and nothing shall quench this thirst except your blood, nothing shall satiate our hunger except your meat. There is no stopping what has been decreed by Allah."

Al-Shehri warned that terrorists would be sending America "the most expensive of gifts," consisting of "coffins followed by coffins, bodies followed by bodies."…